uvm callbacks vs uvm set_type_override

[budisantoso]

Hi everyone,

I am doing conversion from VMM to UVM methodology. In our old VMM bench, we use a lot of callbacks. However in UVM, we can use both callback and set_type_override which can generate same functionality.

How can I determine which one is suitable for my bench conversion between UVM callback and UVM set_type_override?

Thanks,

Budi

[janick]

Depends.

The factory override is static: it will be present for the entire duration of the simulation. It is suitable for things you want to have permanently for the entire test. Also, because SV does not support multiple inheritance, different extensions cannot be arbitrarily combined.

Callbacks are dynamic and will only be present after being registered and can be subsequently removed and/or turned on/off. They are suitable for short-lived extensions you want for only a portion of the run-time (e.g. error injection) and for extensions you want to arbitrarily mix-and-match with others. For example, the report catchers are callbacks.